A case of collagenous gastritis: endoscopic and endocytoscopic features

A 15-year-old boy presented to Ruijin Hospital with complaints of abdominal pain and anemia. During upper gastrointestinal endoscopy, striking nodularity was observed in the gastric body and fundus, presenting as smooth, peninsula-shaped areas ([Fig. 1]). The nodules varied in size [1] [2].

Fig. 1 Endoscopic images showing nodular changes in the mucosa of the gastric body and fundus, with the nodules being of varying sizes.

After a 2-month course of proton pump inhibitors, a follow-up endoscopy revealed persistent diffuse nodularity in the gastric body and fundus, with some of the nodules having become larger and displaying a flattened, disc-like appearance. There was no notable improvement compared with the previous examination. ([Fig. 2]).

Fig. 2 Follow-up endoscopic images showing persistent nodular changes in the gastric body and fundus, with some lesions appearing disc-shaped, and no notable improvement overall.

Narrow-band imaging (NBI) with magnification revealed widened glandular structures with rod-shaped openings. The surrounding areas exhibited glandular atrophy and mild irregularity in the microvascular patterns ([Video 1]). Endocytoscopy showed a regular arrangement of small pit-like epithelial cells with a spiny configuration, and the glandular lumens appeared slit-like with pale-staining nuclei ([Fig. 3]).

The characteristics of the gastric mucosa are shown under white-light endoscopy, narrow-band imaging, and endocytoscopy.Video 1

Fig. 3 Advanced imaging of the nodular mucosa showing: a–c on narrow-band imaging, with and without magnification, glandular widening, with glandular atrophy around the nodules; d–f on endocytoscopy, gland lumens that appear slit-like.

A biopsy was taken from the gastric body, and histopathological examination revealed a thickened (approximately 60 μm) subepithelial collagen layer with associated inflammatory cell infiltration in the lamina propria ([Fig. 4]) [3]. Immunohistochemistry showed positivity for desmin (smooth muscle cells +), SMA (smooth muscle cells +), CD34 (vascular endothelium cells +), S100 (−), Ki67 (partially cells +), Pepsinogen I (chief cells +), AE1/AE3 (epithelial cells +), CK7 (epithelial cells +), and H-K-ATPase (parietal cells +). Masson’s trichrome staining was positive for collagen, and elastin fibers were present in the vascular elastic layer. Based on the clinical, endoscopic, and histopathological findings, a diagnosis of collagenous gastritis was made. The patient is currently under regular endoscopic follow-up.

Fig. 4 Histopathologic appearance on: a hematoxylin and eosin (H&E) staining, showing a thickened subepithelial collagen layer with associated inflammatory cell infiltration in the lamina propria; b Masson’s trichrome staining, showing positivity (blue); c SMA staining, showing positivity of the smooth muscle cells; d desmin staining, showing positivity of the smooth muscle cells.

Endoscopy_UCTN_Code_CCL_1AB_2AD_3AF

Conflict of Interest

The authors declare that they have no conflict of interest.

• References

• 1 Choung RS, Sharma A, Chedid VG. et al. Collagenous gastritis: Characteristics and response to topical budesonide. Clin Gastroenterol Hepatol 2022; 20: 1977-1985
• 2 Hijaz NM, Septer SS, Degaetano J. et al. Clinical outcome of pediatric collagenous gastritis: Case series and review of literature. World J Gastroenterol 2013; 19: 1478-1484
• 3 Wilson C, Thompson K, Hunter C. Nodular collagenous gastritis. J Pediatr Gastroenterol Nutr 2009; 49: 157

Publication History

Article published online:
03 April 2025